Researchers at the Peoria Ag Lab say their new mosquito killer cuts the mustard - literally.
Mustard seed meal is a byproduct of the processing used to make condiments and other products. But when it's soaked in water, it becomes something more potent, for mosquitoes at least.
Mosquitoes are the carriers of many diseases that can be transmitted when they feed on the blood of people or animals. Those include malaria and West Nile Virus.
Dr. Will Hay is a plant physiologist at for the Agricultural Research Service. He said water activates a compound called glucosinolate.
"Those are natural plant defense compounds, that when the plant is damaged by insects, or by pathogens, they'll begin to be broken down and hydrolyzed by myrosinase enzymes," he said.
That process converts the gulcosinolate into a biologically active compound called isothiocyanate that can kill mosquitoes and other insect pests.
Dr. Lina Weiler is an entomologist at Peoria's Ag Lab. She said her unit had heard about Hay's work on the plant side of the equation.
"I said, maybe we should test it with mosquitoes. And so we did, we tried it. And we found it really effective," she said.
She tested four strains of mustard seed meal in water to see how it impacted mosquito larvae. Those included pennycress, white mustard, brown mustard, and garden cress. While all four varieties have an impact, garden cress is most lethal to the insects. 95% die within 24 hours, and 100% are killed off within 48 hours of exposure to garden cress. Mosquito larvae in the control population were still alive.
Because mosquito larvae thrive in stagnant water, Weiler said mustard seed meal is an ideal solution. She said oil extracts are also effective, but mosquito larvae eating the seed meal get a deadlier dose.
Hay said that unlike many synthetic insecticides, mustard seed poses no health threat to humans.
"It is a food product as well as a number of the mustards. So it's really an interesting technology for dealing with mosquitoes," he said.
Weiler said the next steps in research involve testing the impacts of inexpensive mustard seed meal on other insect pests. She's most interested in targeting immature stages of development, before insects can inflict damage and disease on people.
